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Journal Cover Reactive and Functional Polymers
  [SJR: 0.8]   [H-I: 72]   [5 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1381-5148
   Published by Elsevier Homepage  [3041 journals]
  • Water sorption isotherms of molecularly imprinted polymers. Relation
           between water binding and iprodione binding capacity
    • Authors: Manal Bitar; Gaëlle Roudaut; Jacqueline Maalouly; Stéphane Brandès; Régis D Gougeon; Philippe Cayot; Elias Bou-Maroun
      Pages: 1 - 7
      Abstract: Publication date: May 2017
      Source:Reactive and Functional Polymers, Volume 114
      Author(s): Manal Bitar, Gaëlle Roudaut, Jacqueline Maalouly, Stéphane Brandès, Régis D Gougeon, Philippe Cayot, Elias Bou-Maroun
      Molecularly imprinted polymers are often used in aqueous medium in order to recognize specifically a target molecule. The molecular recognition is usually based on hydrogen bonding. In this case, water molecule presents a serious competition towards the target molecule. In this study, the water sorption by molecularly imprinted polymers was studied in aqueous medium. The molecularly imprinted polymers were specific for iprodione fungicide and were prepared using a 24 full factorial experimental design. They were synthesized using EGDMA or TRIM as crosslinker, methacrylamide or styrene as functional monomer and using bulk or precipitation polymerization. The water sorption isotherms were established in a range of water activities 0.05–0.90 at 25°C. The kinetics of water sorption by the polymers were modeled using Peleg's equation. This model shows that polymers having the highest water sorption capacities have high values of imprinting factor. The Guggenheim–Anderson–de Boer isotherm equations were used to fit the equilibrium data and the corresponding parameters were calculated. This model shows that polymers synthesized with EGDMA have higher water sorption capacities than those synthesized with TRIM due to the higher hydrophobicity of the latter. Peleg and Guggenheim–Anderson–de Boer equations satisfactorily modeled the water sorption on the imprinted and non-imprinted polymers. The results obtained from both equations were practically coincident. Principal component analysis was used as a chemometric tool in order to demonstrate that a polymer having a low adsorption energy and a high capacity of water retention could be applied to extract a target molecule from aqueous media.

      PubDate: 2017-03-08T08:06:58Z
      DOI: 10.1016/j.reactfunctpolym.2017.02.012
      Issue No: Vol. 114 (2017)
       
  • A novel method of oil encapsulation in core-shell alginate microcapsules
           by dispersion-inverse gelation technique
    • Authors: Evandro Martins; Denis Poncelet; Denis Renard
      Pages: 49 - 57
      Abstract: Publication date: May 2017
      Source:Reactive and Functional Polymers, Volume 114
      Author(s): Evandro Martins, Denis Poncelet, Denis Renard
      Oil-core microcapsules may be produced by dispersing a calcium solution-oil emulsion into an alginate solution. The release of calcium from the emulsion leads to the gelation of alginate around the oil droplet and therefore to the formation of microcapsules. This work aims to propose a new method of microcapsule production by dispersion-inverse gelation technique. Therefore, W/O emulsions were dispersed in alginate solution and led to the formation of capsules with varying diameters depending on the stirring rate of the alginate bath. The membrane thickness varied between 35 and 200μm depending on the type of emulsion destabilization treatment used. Oil was encapsulated at a yield of 100% allowing the extrapolation of this method at pilot scale. In addition, microcapsules released hydrophilic dye in few hours while hydrophobic dye was retained in the core due to interaction with the oil phase. Core-shell alginate microcapsules produced by dispersion-inverse gelation technique displayed interesting property suitable for applications where actives need to be retained during long times or for volatile compounds.

      PubDate: 2017-03-15T17:17:48Z
      DOI: 10.1016/j.reactfunctpolym.2017.03.006
      Issue No: Vol. 114 (2017)
       
  • Effect of ionic and covalent crosslinking agents on properties of chitosan
           beads and sorption effectiveness of Reactive Black 5 dye
    • Authors: Tomasz Jóźwiak; Urszula Filipkowska; Paula Szymczyk; Joanna Rodziewicz; Artur Mielcarek
      Pages: 58 - 74
      Abstract: Publication date: May 2017
      Source:Reactive and Functional Polymers, Volume 114
      Author(s): Tomasz Jóźwiak, Urszula Filipkowska, Paula Szymczyk, Joanna Rodziewicz, Artur Mielcarek
      This study compared properties of hydrogel chitosan sorbents crosslinked with eight agents, including four ionic ones: sodium citrate, sodium tripolyphosphate, sulfosuccinic acid, and oxalic acid and four covalent ones: glutaraldehyde, epichlorohydrin, trimethylpropane triglycidyl ether, and ethylene glycol diglycidyl ether. The effect of crosslinking process conditions (pH, temperature) and dose of the crosslinking agent on chitosan sorbent stability during sorption and on the effectiveness of Reactive Black 5 dye sorption were examined. The optimal parameters of crosslinking ensuring sorbent stability in acidic solutions and high sorption capability were established for each crosslinking agent tested. The susceptibility of crosslinked sorbents to mechanical damages was analyzed as well. The process of ionic crosslinking was the most effective at the pH value below which hydrogel chitosan sorbent began to dissolve (pH4). The crosslinking temperature ranging from 25 to 60°C had no effect upon sorbent stability. The higher temperature during ionic crosslinking, however, slightly decreased RB5 sorption effectiveness. The ionic crosslinking significantly decrease the susceptibility of chitosan hydrogels to mechanical damages. In the case of covalent crosslinking of chitosan hydrogel beads, the effect of process conditions (pH, temperature) on the properties of the crosslinked sorbent depended on the type of crosslinking agent. The sorbents crosslinked with covalent agents were usually harder but also more fragile, and therefore more susceptible to mechanical damages.
      Graphical abstract image

      PubDate: 2017-03-21T08:34:55Z
      DOI: 10.1016/j.reactfunctpolym.2017.03.007
      Issue No: Vol. 114 (2017)
       
  • Photo-induced reversible addition-fragmentation chain transfer (RAFT)
           polymerization of acrylonitrile at ambient temperature: A simple system to
           obtain high-molecular-weight polyacrylonitrile
    • Authors: Jiajia Li; Chunlai Ding; Zhengbiao Zhang; Jian Zhu; Xiulin Zhu
      Pages: 1 - 5
      Abstract: Publication date: April 2017
      Source:Reactive and Functional Polymers, Volume 113
      Author(s): Jiajia Li, Chunlai Ding, Zhengbiao Zhang, Jian Zhu, Xiulin Zhu
      Photo-induced reversible addition-fragmentation chain transfer (RAFT) polymerization of acrylonitrile was performed in a two-component system using 2-cyano-2-propyl dodecyl trithiocarbonate as the initiation-regulator dual-functional agent. The polymerization was carried out under mild conditions, e.g. under irradiation of blue light-emitting diode light at ambient temperature. Well-controlled polymers with high molecular weight and narrow molecular weight distribution were obtained. The light on and off experiments showed photosensitivity of this polymerization system. The structure of the obtained polymers was characterized by GPC and NMR. Polymers with molecular weight as high as M n =286,300g/mol could be obtained in optimized conditions.
      Graphical abstract image

      PubDate: 2017-02-14T17:32:24Z
      DOI: 10.1016/j.reactfunctpolym.2017.02.003
      Issue No: Vol. 113 (2017)
       
  • Speeding up heterogeneous catalysis with an improved highly reusable
           catalyst for the preparation of enantioenriched secondary alcohols
    • Authors: Esther M. Sánchez-Carnerero; Rafael Sandoval-Torrientes; Javier Urieta-Mora; Florencio Moreno; Beatriz L. Maroto; Santiago de la Moya
      Pages: 23 - 30
      Abstract: Publication date: April 2017
      Source:Reactive and Functional Polymers, Volume 113
      Author(s): Esther M. Sánchez-Carnerero, Rafael Sandoval-Torrientes, Javier Urieta-Mora, Florencio Moreno, Beatriz L. Maroto, Santiago de la Moya
      A new catalytic heterogeneous system, very efficient and highly reusable, for the preparation of enantioenriched secondary alcohols through the addition of diethylzinc to benzaldehyde has been developed. This system is based on a chiral bis(hydroxyamide) ligand supported on crosslinked polystyrene. The catalyst has been shown to be very efficient, leading to the corresponding secondary alcohol with an enantiomeric excess of 93% in a time as short as 2h and using just 4% of the heterogeneous catalyst and just 1.5 equivalents of the organozinc reagent. We have demonstrated that the new catalyst is very stable and can be efficiently recycled with no decrease in yield or enantioselectivity. The presented system has an unquestionable interest for the potential transfer of the reaction to the industry by using catalytic fluidized-bed reactors.
      Graphical abstract image

      PubDate: 2017-02-21T17:58:06Z
      DOI: 10.1016/j.reactfunctpolym.2017.02.008
      Issue No: Vol. 113 (2017)
       
  • Pyrocatechol-modified resins for boron recovery from water: Synthesis,
           adsorption and isotopic separation studies
    • Authors: Jiafei Lyu; Zhouliangzi Zeng; Nan Zhang; Hongxu Liu; Peng Bai; Xianghai Guo
      Pages: 1 - 8
      Abstract: Publication date: Available online 2 January 2017
      Source:Reactive and Functional Polymers
      Author(s): Jiafei Lyu, Zhouliangzi Zeng, Nan Zhang, Hongxu Liu, Peng Bai, Xianghai Guo
      Two kinds of pyrocatechols, pyrocatechol (CL) and nitropyrocatechol (NCL), were chosen by the conductive value change (Δ) they cause in the boric acid-polyol solutions, and corresponding modified resins (CL-RESIN and NCL-RESIN) were synthesized by new methodology for effective boron removal and isotopic separation. The optimized boron adsorption occurs at pH=9.06 for CL-RESIN, and pH=6.70 for NCL-RESIN, with the maximum adsorption capacity 0.7886mmol·g−1 and 0.7931mmol·g−1, which were comparable to commercial IRA 743. Boron adsorption on prepared resins was saturated within 12h and can be well described by pseudo-second-order kinetic model. Freundlich isotherm model fits well at low boron concentration while Langmuir isotherm model fits better at high concentration. Furthermore, the boron isotopic separation factors S on two prepared resins are 1.080 for CL-RESIN and 1.140 for NCL-RESIN, which are far higher than all previous results. Boron removal and isotopic separation capacities make it possible that three problems, boron removal, isotopic separation and boron reusability, can be addressed in single adsorption process.
      Graphical abstract image

      PubDate: 2017-01-06T10:27:11Z
      DOI: 10.1016/j.reactfunctpolym.2016.12.016
      Issue No: Vol. 112 (2017)
       
  • Properties of native and oxidized corn starch/polystyrene blends under
           conditions of reactive extrusion using zinc octanoate as a catalyst
    • Authors: Tomy J. Gutiérrez; Vera A. Alvarez
      Pages: 33 - 44
      Abstract: Publication date: March 2017
      Source:Reactive and Functional Polymers, Volume 112
      Author(s): Tomy J. Gutiérrez, Vera A. Alvarez
      Native and oxidized corn (Zea mays) starch/polystyrene (PS) blends containing glycerol as a plasticizer were prepared by reactive extrusion in a twin-screw extruder using zinc octanoate (Zn(Oct)2) as a catalyst, followed by compression molding. Blends were characterized in terms of their: average molecular weight, moisture content, infrared (FTIR) spectra, water solubility, thermogravimetric (TGA) properties, differential scanning calorimetry (DSC) curves, X-ray diffraction (XDR) patterns, stability in acidic or alkaline medium, and microstructural, mechanical and antimicrobial properties. The results clearly show that the catalyst used produced cross-linking between the starch and PS, and that the oxidative modification of the starch increased its reactivity. This was demonstrated by the increase in molecular weight, thermal resistance, and hydrophobicity of films prepared from the oxidized starch/PS plus catalyst. This increase in hydrophobicity of the starch modified systems was due to the carboxyl and carbonyl groups introduced into the starch structure. As a result, phase separation was more obvious, despite the increase in the cross-linking rate between the oxidized starch and the PS. Finally, none of the films showed signs of swelling or antimicrobial activity. Nonetheless, the catalyst exhibited excellent antimicrobial activity against the pathogenic microorganisms evaluated.

      PubDate: 2017-01-14T10:36:15Z
      DOI: 10.1016/j.reactfunctpolym.2017.01.002
      Issue No: Vol. 112 (2017)
       
  • Morphology control of anisotropic nonspherical functional polymeric
           particles by one-pot dispersion polymerization
    • Authors: Huifang Shen; Xiaolin Du; Xiaolin Ren; Yuhui Xie; Xinxin Sheng; Xinya Zhang
      Pages: 53 - 59
      Abstract: Publication date: March 2017
      Source:Reactive and Functional Polymers, Volume 112
      Author(s): Huifang Shen, Xiaolin Du, Xiaolin Ren, Yuhui Xie, Xinxin Sheng, Xinya Zhang
      A feasible and versatile route for a large-scale synthesis of monodisperse nonspherical functional polymer particles by one-pot dispersion polymerization was demonstrated. The particle morphology could be precisely tuned by varying the divinylbenzene (DVB) concentration, the start feeding time of DVB, the total feeding time of DVB, the styrene (St) mass ratio of stage I/stage II, and the solvent polarity. Sphere-like, polyhedron-like, and red blood cells (RBC)-like particles with dimples or smooth surface were obtained. In addition, the formation mechanism of these nonspherical particles was ascribed to the phase separation induced by the uneven distribution of cross-linked network. Because of the incompatibility between St homopolymer chain and cross-linked network, St homopolymer chain was forced to move to those zones where the blend was allowed. The particle surface was forced to distort, leading to the formation of particles with various morphologies.

      PubDate: 2017-01-21T10:43:51Z
      DOI: 10.1016/j.reactfunctpolym.2017.01.006
      Issue No: Vol. 112 (2017)
       
  • Temperature responsive copolymer as support for metal nanoparticle
           catalyst: A recyclable catalytic system
    • Authors: Yueyue Dong; Qingfang Wang; Jingtuo Wang; Yanli Ma; Danhong Wang; Zhijie Wu; Munire Abudkremb; Minghui Zhang
      Pages: 60 - 67
      Abstract: Publication date: March 2017
      Source:Reactive and Functional Polymers, Volume 112
      Author(s): Yueyue Dong, Qingfang Wang, Jingtuo Wang, Yanli Ma, Danhong Wang, Zhijie Wu, Munire Abudkremb, Minghui Zhang
      A recyclable catalytic system was developed by using a temperature responsive poly(acrylamide-co-acrylonitrile) (P(AAm-co-AN)) copolymer with an upper critical solution temperature (UCST). Palladium nanoparticles (NPs) immobilized on P(AAm-co-AN) copolymer were synthesized by the chemical reduction method using NaBH4. TEM characterizations showed the highly dispersed and small (~3nm) Pd nanoparticles formed on the surface of the P(AAm-co-AN) copolymer. UV–Vis measurements indicated the increase of UCST of P(AAm-co-AN) from 30 to 35°C after the deposition of Pd metal. P(AAm-co-AN) supported Pd catalyst showed high activity in allyl alcohol hydrogenation and facile separation and recovery via sharp solubility changes of catalyst by cooling below UCST.
      Graphical abstract image

      PubDate: 2017-01-21T10:43:51Z
      DOI: 10.1016/j.reactfunctpolym.2017.01.004
      Issue No: Vol. 112 (2017)
       
  • Fluoride removal from aqueous solution by Zirconium-Chitosan/Graphene
           Oxide Membrane
    • Authors: Jing Zhang; Nan Chen; Miao Li; Panyun Su; Chuanping Feng
      Abstract: Publication date: Available online 19 March 2017
      Source:Reactive and Functional Polymers
      Author(s): Jing Zhang, Nan Chen, Miao Li, Panyun Su, Chuanping Feng
      A Zirconium-Chitosan/Graphene Oxide (Zr-CTS/GO) Membrane adsorbent was applied for fluoride removal from aqueous solution. The effects of different compositions, dose, pH, and initial fluoride concentration were investigated. Results showed that the membrane could effectively remove fluoride within a wide pH range of 3–11. The data fitted the Freundlich isotherm model well, indicating that fluoride adsorption occurred on heterogeneous Zr-CTS/GO membrane surfaces probably in a multilayer form. The kinetic studies showed that the adsorption reached equilibrium within 45min, and the maximum adsorption capacity was calculated to be 29.0588mg/g by Two-site Langmuir isotherm model. X-ray photoelectron spectroscopy (XPS), and extended X-ray absorption fine structure spectroscopy (EXAFS) were used to elucidate the adsorption mechanism. The results revealed that Zr(IV) species reacted with oxygen functional groups from the CTS/GO complex, and ZrF species formed partly through fluoride ions exchanged with chloride ions and OH and partly through chemical rearrangement. The findings indicate that Zr-CTS/GO is a promising adsorbent for fluoride removal with a quite short contact time and a wide optimum pH range.
      Graphical abstract image

      PubDate: 2017-03-21T08:34:55Z
      DOI: 10.1016/j.reactfunctpolym.2017.03.008
       
  • Photo-crosslinked thiol-ene based hybrid polymeric sensor for humidity
           detection
    • Authors: Aslı Beyler Çiğil; Hüsnü Cankurtaran; Memet Vezir Kahraman
      Abstract: Publication date: Available online 9 March 2017
      Source:Reactive and Functional Polymers
      Author(s): Aslı Beyler Çiğil, Hüsnü Cankurtaran, Memet Vezir Kahraman
      This study describes the preparation and characterization of new surface modified carbon nanotube particles (CNT) containing thiol-ene based hybrid polymers by photo-polymerization of pentaerythritol tetrakis, glyoxal bis(diallyl acetal), trimethylol propane triacrylate monomers and their usage for humidity sensing. CNT surface was photografted with polyethylene glycol acrylate (PEGA) to produce hydroxyl groups. Hydroxyl functionalized CNT/PEGAs were acrylated using isocyanatoethyl methacrylate (IEM) in order to improve the dispersion and interfacial interaction in composites. Furthermore, different amounts of gold nanoparticles containing compositions were also prepared. The humidity sensing properties of two samples were investigated by impedance measurements. The effects of CNT/Au modification, the applied potential bias and alternating current frequency on the electrical properties and the humidity sensitivity were determined. FCNT0 and FCNT5Au0.5 exhibit extremely high selectivity against humidity compare to various solvents; ethanol, acetone, methyl acetate and chloroform. FCNT0 has a reasonable good sensor performance for humidity measurements. It has high sensitivity, selectivity, stability, response/recovery and linear response properties in a full range of humidity measurements.

      PubDate: 2017-03-15T17:17:48Z
      DOI: 10.1016/j.reactfunctpolym.2017.03.002
       
  • Natural based eumelanin nanoparticles functionalization and preliminary
           evaluation as carrier for gentamicin
    • Authors: Antonella De Trizio; Pathomthat Srisuk; Rui R. Costa; Alexandra G. Fraga; Tiziana Modena; Ida Genta; Rossella Dorati; Jorge Pedrosa; Bice Conti; Vitor M. Correlo; Rui L. Reis
      Abstract: Publication date: Available online 7 March 2017
      Source:Reactive and Functional Polymers
      Author(s): Antonella De Trizio, Pathomthat Srisuk, Rui R. Costa, Alexandra G. Fraga, Tiziana Modena, Ida Genta, Rossella Dorati, Jorge Pedrosa, Bice Conti, Vitor M. Correlo, Rui L. Reis
      Purpose of the work was to modified natural based eumelanin nanoparticles surface by dopamine self-polymerization (FEUNp), facilitating conjugation through polydopamine bioactive functional groups and improving nanoparticle surface hydrophilicity. SEM, TEM, and AFM characterization confirmed FEUNp spherical shape (230.04±8.25nm) and their polydopamine coating. Individual indole or indoline structure spectrum at 1600cm−1 and C:N mass 9.08 was highlighted by FTIR and XPS analysis respectively. Quartz-crystal microbalance with dissipation monitoring (QCM-D) and thermal gravimetric analysis (TGA) showed successful polydopamine adsorption to eumelanin nanoparticles surface, a weight ratio of eumelanin nanoparticles/dopamine of 1/2.46 in the wet state and 1/0.20 in the dry state; the −36.60±0.45mV negatively surface charges confirms the presence of PD covering. FEUNp were loaded with gentamicin sulfate, for application in infectious diseases therapies, such as osteomyelitis. Nanoparticles drug entrapment efficiency was 32.42±3.21%, and ζ-potential close to neutrality (−1.84±0.58mV). FEUNp-GS antimicrobial effect was tested on Staphylococcus aureus and Escherichia coli showing gentamicin 24h sustained release from FEUNp-GS. IC50 and IC90 were 110.60μg/mL and 216.39μg/mL against S. aureus, and 54.13μg/mL and 101.25μg/mL against E. coli. The results are promising for FEUNp-GS as delivery system potentially useful diverse administration routes.

      PubDate: 2017-03-08T08:06:58Z
      DOI: 10.1016/j.reactfunctpolym.2017.03.004
       
  • On the kinetics of block copolymer mediated palladium quantum dot
           synthesis: Application in reduction of Cr(VI) to Cr(III)
    • Authors: Zarina Ansari; Abhijit Saha; Kamalika Sen
      Abstract: Publication date: Available online 7 March 2017
      Source:Reactive and Functional Polymers
      Author(s): Zarina Ansari, Abhijit Saha, Kamalika Sen
      In this work we have designed a simple, eco-friendly, one-pot method for the synthesis of palladium nanoparticles of quantum dot dimension (PdQDs) using a non-toxic, biocompatible block co polymer which functions as a reducing and stabilizing agent during the synthesis. The entire synthesis is free from any especial experimental set up and reaction conditions. These QDs were characterized by several well know characterization techniques such as UV–vis spectroscopy (UV–vis), transmission electron microscopy (TEM), Fourier transform infra-red spectroscopy (FTIR), dynamic light scattering (DLS), and ξ potential measurements. The transformation of a yellow solution into dark brown solution was indicative of the formation of the PdQDs. The kinetics of this reaction was monitored using a time scan absorption measurement which reveals a sigmoidal curve, a signature of noble metal nanoparticles. The rate of nucleation and growth were calculated using Finke and Watzky model. The synthesized colloidal PdQDs were employed for the reduction of environmentally toxic Cr(VI) to safer Cr(III). The reaction was catalyzed by the PdQDs in presence of acetic acid and was dependent on the concentration of both. The order and rate constant of the reduction reaction was calculated. A comparatively faster and complete reduction of Cr(VI) to Cr(III) using this catalysis was achieved at room temperature in presence γ irradiation, thus making the method more effective in its approach for bulk remediation of Cr(VI).

      PubDate: 2017-03-08T08:06:58Z
      DOI: 10.1016/j.reactfunctpolym.2017.03.005
       
  • One-pot synthesis of supported hydrogel membranes via emulsion templating
    • Authors: Qixiang Jiang; Angelika Menner; Alexander Bismarck
      Abstract: Publication date: Available online 6 March 2017
      Source:Reactive and Functional Polymers
      Author(s): Qixiang Jiang, Angelika Menner, Alexander Bismarck
      Supported hydrogel membranes were produced by one-pot synthesis by the polymerisation of suitable emulsion templates. High internal phase emulsions (HIPEs) with styrene (St), divinylbenzene (DVB) and ethylhexyl acrylate (EHA) in the continuous phase and methacrylic acid (MAA) in the internal phase were polymerised to prepare poly(MAA) hydrogel grafted poly(St-co-DVB-co-EHA) poly(merised)HIPEs. By changing the concentration of the crosslinker, N,N′-methylenebisacrylamide, in the internal phase of the emulsion template the crosslinking density of the grafted poly(MAA) was tuned. The presence of the hydrogel was indicated by a change in pore morphology, e.g. coverage of the pore throats and the wrinkled pore wall surface, and the increase in the density of the composite polyHIPEs as compared to control polyHIPEs. Moreover, the increase in foam density and reduction of porosity were related to the crosslinking degree of the hydrogel. The water uptake of the composite polyHIPEs exceeded the pore volume of the polyHIPE scaffold supporting the grafted hydrogel. The permeability and rejection of aqueous solutions of polyethylene glycol (PEG) by the hydrogel grafted polyHIPE membranes were strongly pH dependent, the permeability decreased and the rejection of PEG increased with increasing pH due to the increased swelling of the hydrogel. A 91% rejection of 50kDa PEG for polyHIPE supported hydrogel membranes has been identified, which qualifies such membranes for ultrafiltration applications.
      Graphical abstract image

      PubDate: 2017-03-08T08:06:58Z
      DOI: 10.1016/j.reactfunctpolym.2017.03.003
       
  • Developing a potential antibacterial long-term degradable electrospun
           gelatin-based composites mats for wound dressing applications
    • Authors: R. Morsy; M. Hosny; F. Reicha; T. Elnimr
      Abstract: Publication date: Available online 4 March 2017
      Source:Reactive and Functional Polymers
      Author(s): R. Morsy, M. Hosny, F. Reicha, T. Elnimr
      Antibacterial electrospun fibrous membranes are widely applied as dressings for treatment the wounds and burns. However, developing long-term gelatin-based fibrous membrane is still the main challenge inhibiting their uses for long-term treatments. Novel antibacterial electrospun gelatin-based mats were introduced by combining gelatin, glycerol, glucose and silver nanoparticles (Ag NPs), which together could exhibit optimal physicochemical characteristics as long-term electrospun fibrous mats. Therefore, Ag NPs were synthesized in-situ within the acidic electrospun solutions during preparing electrospun gelatin-glycerol-Ag NPs (GEL-GLY-Ag) and gelatin-glycerol-glucose-Ag NPs (GEL-GLY-GLU-Ag) mats. Conventional spectroscopic techniques based on XRD, FTIR, SEM, DTA, and water uptake-degradation tests and antibacterial studies were used to characterize the preparations. The results showed that the electrospun gelatin-based composites mats revealed free beads dense fibrous textures, and exhibited a high water uptake and long-term degradation behavior. The Ag NPs could be successfully synthesized in-situ within electrospinning solutions and the results confirmed that the in-situ prepared Ag NPs enhanced the antibacterial activity of electrospun mats against positive and negative bacteria.

      PubDate: 2017-03-08T08:06:58Z
      DOI: 10.1016/j.reactfunctpolym.2017.03.001
       
  • Polymeric quaternary ammonium salt activity against Fusarium oxysporum f.
           sp. cubense race 4: Synthesis, structure-activity relationship and mode of
           action
    • Authors: Zhenfeng Huang; Runqi Liuyang; Chengyun Dong; Yufeng Lei; Anqiang Zhang; Yaling Lin
      Abstract: Publication date: Available online 3 March 2017
      Source:Reactive and Functional Polymers
      Author(s): Zhenfeng Huang, Runqi Liuyang, Chengyun Dong, Yufeng Lei, Anqiang Zhang, Yaling Lin
      Polymeric quaternary ammonium salts (PQAS) have been widely used to prevent microbial contamination, but little is known about their activity against phytopathogenic fungi. Our previous report described the synthesis of two novel PQAS, namely a homopolymer of (2-methacrylamido) propyltetrabenzyldimethylammonium chloride (PQD-BC) and dimethylaminopropyl benzyl chloride-grafted polysiloxanes (PDMS-g-BC); we demonstrated their structure-activity relationship against phytopathogenic fungi such as R. solani and Fusarium oxysporum f. sp. cubense tropical race 4 (Foc4). Here, we analyzed the structure-activity relationship and toxicity mechanism of these compounds at the molecular level against Foc4 compared with the low molecular-weight quaternary ammonium salt benzalkonium chloride (BC). The results revealed that PQD-BC and PDMS-g-BC application inhibited the growth of Foc4 in a concentration-dependent manner and that PDMS-g-BC exhibited higher activity than PQD-BC. In addition, these polymers were found to induce cell death in Foc4 by disrupting the cellular structure integrity, such as the loss of the cell wall and plasma membrane integrity and oxidative stress (lipid peroxidation), leading to the release of intracellular contents and inducing mitochondrial dysfunction and interference with genomic DNA. The newly elucidated mechanism provides possible applications in which PQAS can be used against phytopathogenic fungi.

      PubDate: 2017-03-08T08:06:58Z
      DOI: 10.1016/j.reactfunctpolym.2017.02.013
       
  • Dispersion of single-walled carbon nanotubes in an aqueous medium by using
           a cyclic copolymer
    • Authors: Ning Zhang; Di Zhou; Nianchen Zhou; Zhengbiao Zhang; Xiulin Zhu
      Abstract: Publication date: Available online 24 February 2017
      Source:Reactive and Functional Polymers
      Author(s): Ning Zhang, Di Zhou, Nianchen Zhou, Zhengbiao Zhang, Xiulin Zhu
      A cyclic copolymer, poly(methoxy-PEG acrylate-co-3-(4-benzoylphenoxy) propyl acrylate), was successfully synthesized by Cu(0)-mediated controlled radical polymerization and Cu(I)-catalyzed azide–alkyne cycloaddition “click” chemistry. The self-assembly behaviours of the linear and cyclic copolymers were investigated. Subsequently, the linear and cyclic copolymers were used to disperse the single-walled carbon nanotubes (SWCNTs) in an aqueous medium. The results showed that cyclic copolymers could form uniformly stable, spherical morphologies by self-assembly more easily than their linear counterparts under the same conditions. Cyclic copolymers were also found to better disperse SWCNTs, thereby extending the applications of SWCNTs in an aqueous medium.

      PubDate: 2017-02-28T18:16:52Z
      DOI: 10.1016/j.reactfunctpolym.2017.02.011
       
  • Understanding the curing kinetics and rheological behaviour of a new
           benzoxazine resin for carbon fibre composites
    • Authors: V. García-Martínez; M.R. Gude; A. Ureña
      Abstract: Publication date: Available online 20 February 2017
      Source:Reactive and Functional Polymers
      Author(s): V. García-Martínez, M.R. Gude, A. Ureña
      The curing kinetics and viscoelastic properties of a benzoxazine resin intended for liquid resin infusion and resin transfer moulding processes was investigated by differential scanning calorimetry (DSC) and rheological experiments. An autocatalytic kinetic model was proposed and all kinetic parameters including reactions orders and activation energy were determined. The curing kinetic equation obtained by linear model-fitting of non-isothermal experiments matched reasonably well with the experimental results from both non-isothermal and isothermal tests. The evolution of viscoelastic properties, such as storage modulus (G′), loss modulus (G″) and complex viscosity (IŋI*) was recorded during the curing reaction. Gelation times at several isothermal temperatures between 170 and 210°C were obtained and the activation energies for curing and gelation were calculated. Finally, quasi-isothermal DSC experiments were carried out in order to obtain the vitrification times, using the inflexion point of the reversing heat capacity (Cp-rev).

      PubDate: 2017-02-21T17:58:06Z
      DOI: 10.1016/j.reactfunctpolym.2017.02.005
       
  • Performance of poly(3-hexylthiophene) in bulk heterojunction solar cells:
           Influence of polymer size and size distribution
    • Authors: Jose Jonathan Rubio Arias; Maria de Fatima Vieira Marques
      Abstract: Publication date: Available online 20 February 2017
      Source:Reactive and Functional Polymers
      Author(s): Jose Jonathan Rubio Arias, Maria de Fatima Vieira Marques
      Poly(3-hexylthiophene) (P3HT) is a versatile polymer that has been deeply studied as a material for electronic devices and also for organic solar cells. This study is a recompilation of the molar mass and polydispersity dependence studies on its charge carrier mobility, crystallinity and PCBM based solar cells. Through the examination of different works, it has been demonstrated the necessity of increasing annealing temperature along molar mass in order to obtain better values of power conversion efficiency. Due to the probable polymer degradation, thermal analysis must be performed in order to approach the observed trend of increasing charge carrier mobility along with molar mass. The maximum power conversion efficiency (PCE) value reported for P3HT: PCBM device is 4.42% for a P3HT with number average molar mass Mn of 43kDa and polydispersity index (PDI) of 2.1. This latter parameter was found to play an important role in the solar cell performance, and it was observed that a narrow molar mass distribution is not always desirable, especially for polymers with high molar masses.

      PubDate: 2017-02-21T17:58:06Z
      DOI: 10.1016/j.reactfunctpolym.2017.02.009
       
  • Hexa(eugenol)cyclotriphosphazene modified bismaleimide resins with unique
           thermal stability and flame retardancy
    • Authors: Xinfang Zhang; Raheel Akram; Shuangkun Zhang; Hanlin Ma; Zhanpeng Wu; Dezhen Wu
      Abstract: Publication date: Available online 17 February 2017
      Source:Reactive and Functional Polymers
      Author(s): Xinfang Zhang, Raheel Akram, Shuangkun Zhang, Hanlin Ma, Zhanpeng Wu, Dezhen Wu
      We have successfully synthesized high performance bismaleimide based hexa(eugenol)cyclotriphosphazene (HECTP) resin which possess good mechanical, excellent thermal stability at high temperature and flame retardant properties. Hexa(eugenol)cyclotriphosphazene (HECTP) were obtained by the reaction of sodium, eugenol (EG) and hexachlorocyclotriphosphazene (HCCP). 1H NMR and 31P NMR were employed to confirm the formation of (HECTP). NMR analysis of the HECTP showed that all chlorine (Cl) atoms of HCCP were successfully substituted by sodium (Na) atom of the sodium eugenol. The 4,4′-bismaleimidodiphenylmethane (BMI) was reacted with EG and HECTP to produce BMI-EG1/1 resin with maleimide/allyl unit ratios of 1/1 and BMI-HECTP resins with maleimide/allyl unit ratios of 1/1, 1.5/1, 2/1, 2.5/1 and 3/1, respectively. The characterization results of TGA showed that HECTP could greatly enhance the thermal stability, the residues of BMI-HECTP 1/1, 1.5/1, 2/1, 2.5/1, 3/1 resins were 61%, 63.9%, 68%, 66.2% and 65% respectively. Besides, their flame retardancy were excellent, and the LOI values of all BMI-HECTP resins were 39%, 48.4%, 50.1%, 49.8% and 48.9% respectively, and the results of all BMI-HECTP resins at UL-94 vertical burning tests reached V-0 level and extinguished at once after removing the flame agitator. The flexural strength (77.77–100.03MPa) of all BMI-HECTP resins was higher than that of BMI-EG1/1 (73.93MPa). Furthermore, the impact strength of BMI-HECTP1/1, BMI-HECTP1.5/1 and BMI-HECTP 2/1 were 12.4, 13.3 and 11.94KJ·m−2, respectively, higher than that of BMI-EG1/1(9.42KJ·m−2), except for BMI-HECTP 2.5/1 (9.19KJ·m−2) and BMI-HECTP3/1 (6.14KJ·m−2).

      PubDate: 2017-02-21T17:58:06Z
      DOI: 10.1016/j.reactfunctpolym.2017.02.010
       
  • Effect of support properties on preparation process and adsorption
           performances of solvent impregnated resins
    • Authors: Yongping Tang; Shenxu Bao; Yimin Zhang; Liang Liang
      Abstract: Publication date: Available online 16 February 2017
      Source:Reactive and Functional Polymers
      Author(s): Yongping Tang, Shenxu Bao, Yimin Zhang, Liang Liang
      The effect of support properties on preparation process and adsorption performances of solvent impregnated resins (SIRs) has been studied. Five SIRs were prepared by impregnating di(2-ethylhexyl)phosphoric acid (D2EHPA) in five macroporous absorbent resins (MARs), respectively and used to extract V(IV) from aqueous solutions. The impregnation equilibrium can be fast achieved for the MARs with bigger pore size and specific surface area, where D2EHPA is preferentially adsorbed in the micropores approximately as wall-spreading to form monolayer films, resulting in the relatively high utilization efficiency of extractant and stability of the SIRs. However, the extractant is more likely to accumulate in the macropores and/or mesopores than in the micropores, which leads to the higher mass ratio of extractant and pore-filling percentage in the SIRs with abundant macropores and/or mesopores. D2EHPA can be adsorbed on XAD-7HP fabricated with poly(methyl methacrylate) by virtue of relatively strong Hydrogen-bond, thus it can exist not only inside the pores but also on the surface of the resin, which causes the high mass ratio of extractant and extremely high pore-filling percentage although it contains the minimum pore volume. The relatively strong hydrogen-bond between XAD-7HP and D2EHPA is also believed to be responsible for its high adsorption capacity for V(IV) and utilization efficiency of the impregnated extractant.

      PubDate: 2017-02-21T17:58:06Z
      DOI: 10.1016/j.reactfunctpolym.2017.02.006
       
  • Evaluation of the temperature and molecular weight dependent migration of
           di(2-ethylhexyl) phthalate from isotactic polypropylene composites
    • Authors: Adhimoorthy Prasannan; Jheng-Jun Jhu; Chih-Jen Wu; Shuian-Yin Lin; Hsieh-Chih Tsai
      Abstract: Publication date: Available online 14 February 2017
      Source:Reactive and Functional Polymers
      Author(s): Adhimoorthy Prasannan, Jheng-Jun Jhu, Chih-Jen Wu, Shuian-Yin Lin, Hsieh-Chih Tsai
      The development of a process for the bioremediation of di(2-ethylhexyl) phthalate (DEHP) blended in various polymers, with a low DEHP release rate, has become an essential mission in the packaging materials industry, especially for blood-component storage materials. Hence, polypropylene and DEHP composites were prepared to evaluate their DEHP release behavior at 90°C and 25°C. The physical and chemical properties of the composites were evaluated with various analytical tools. Polypropylene of three different molecular weights was used to compare the different DEHP releasing rates. The incorporation and migration of DEHP significantly followed the crystalline nature of the polymer matrix. The temperature-dependent migration behavior was evaluated by UV–Vis spectroscopy and LC/MS analyses. Among the three different molecular weight PP/DEHP composites, a significantly lower amount of DEHP was released from the higher molecular weight polymer composite due to its enriched crystalline nature. Moreover, the release behavior of DEHP was affected by the molecular weight and crystalline nature of PP, which can strongly hold the plasticizer, and therefore slow down its release. The high molecular weight iPP/DEHP composite may be suitable for blood-component backing materials because of its lower DEHP migration.

      PubDate: 2017-02-14T17:32:24Z
      DOI: 10.1016/j.reactfunctpolym.2017.02.007
       
  • Aspartic acid grafting on cellulose and chitosan for enhanced Nd(III)
           sorption
    • Authors: Ahmed A. Galhoum; Khalid M. Hassan; Osman A. Desouky; Ahmed M. Masoud; Takaya Akashi; Yuka Sakai; Eric Guibal
      Abstract: Publication date: Available online 13 February 2017
      Source:Reactive and Functional Polymers
      Author(s): Ahmed A. Galhoum, Khalid M. Hassan, Osman A. Desouky, Ahmed M. Masoud, Takaya Akashi, Yuka Sakai, Eric Guibal
      Cellulose and chitosan have intrinsic sorption properties for Nd(III); however, their efficiency for metal recovery can be easily improved by a relatively simple chemical modification. The grating of aspartic acid via an intermediary chlorination step of the polysaccharides allows increasing sorption capacities due to the specific reactivity of carboxylate groups. The grafting process is confirmed by elemental analysis, FTIR spectrometry, while the physical properties of the derivatives are characterized by XRD (crystallinity) and TGA (thermogravimetric analysis). The sorption properties are carried out by investigating the effect of the pH, studying the uptake kinetics and the evaluating the thermodynamics (sorption isotherms). The sorption properties of modified sorbents are systematically compared to the performance of raw materials. Sorption capacity is doubled after grafting aspartic acid onto biopolymer backbone. Sorption isotherms are described by the Freundlich and the Langmuir equation and maximum sorption capacities reach up to 77–80mgNdg−1 at pH5. The uptake kinetics are described by the pseudo-first order reaction rate and under selected experimental conditions the equilibrium is reached within 3h of contact. The sorption is spontaneous, endothermic. Metal desorption can be successfully performed with 0.5M nitric acid and the sorbents can be recycled for at least 4 sorption/desorption cycles without significant loss in sorption/desorption performances.

      PubDate: 2017-02-14T17:32:24Z
      DOI: 10.1016/j.reactfunctpolym.2017.02.001
       
  • Characterization of brominated natural rubber by solution-state 2D NMR
           spectroscopy
    • Authors: Nuorn Choothong; Kenichiro Kosugi; Yoshimasa Yamamoto; Seiichi Kawahara
      Abstract: Publication date: Available online 10 February 2017
      Source:Reactive and Functional Polymers
      Author(s): Nuorn Choothong, Kenichiro Kosugi, Yoshimasa Yamamoto, Seiichi Kawahara
      Bromination of natural rubber was analyzed through nuclear magnetic resonance (NMR) spectroscopy, in which small 1H and 13C NMR signals, appearing after bromination of natural rubber, were positively assigned by 1D and 2D NMR measurement. The brominated natural rubber (BrDPNR) was prepared by bromination of deproteinized natural rubber (DPNR) with N-bromosuccinimide (NBS) in dichloromethane at 303K for 3h under a nitrogen atmosphere. The 13C NMR signals at 20.5, 22, 29, 29.8, 35.8, 40 and 112.4ppm were assigned to the primary and the secondary carbons of the brominated trans-1,4-isoprene units, whereas the signals at 24.5 and 32.6ppm were assigned to the primary and the secondary carbons of the brominated cis-1,4-isoprene units. During the bromination of DPNR with NBS, the isoprene units undergo cis-trans isomerization.
      Graphical abstract image

      PubDate: 2017-02-14T17:32:24Z
      DOI: 10.1016/j.reactfunctpolym.2017.02.004
       
  • Preparation of PPy/cellulose fibre as an effective potassium diclofenac
           adsorbent
    • Authors: Bruna Carneiro Pires; Flávia Viana Avelar Dutra; Tienne Aparecida Nascimento; Keyller Bastos Borges
      Abstract: Publication date: Available online 10 February 2017
      Source:Reactive and Functional Polymers
      Author(s): Bruna Carneiro Pires, Flávia Viana Avelar Dutra, Tienne Aparecida Nascimento, Keyller Bastos Borges
      Cellulose fibre (CF) has been widely employed as an adsorbent because of its effective capacity for adsorbing toxic components of cigarette smoke. There is a lack of studies of CF adsorbing pharmaceuticals from water. Herein, we evaluated the adsorption of potassium diclofenac (PD) from an aqueous medium by CF. In addition, we developed and prepared CF covered with polypyrrole (PPy) to improve the adsorptive capacity for removal of PD. From the infrared characterization, the main bands related to the functional groups of each component, PPy and CF, were identified; in thermogravimetry it was observed that both the CF and composite support relatively high temperatures and in the scanning electron microscopy it was possible to observe that the composite has a fibrous structure related to CF in which PPy particles are aggregated. In adsorption studies of PD in an aqueous medium, the pH, the contact time between the material and analyte and equilibrium concentration were evaluated. The first study carried out was the influence of pH on the adsorbed amount of PD, the optimum pH chosen for the experiments being 2.0 and 6.0 for CF and PPy/CF, respectively. In the kinetic study, adsorption occurred rapidly and equilibrium times were achieved within 30min (CF) and 15min (PPy/CF). The kinetic data were analysed using four models: pseudo-first-order, pseudo-second-order, Elovich and intraparticle diffusion and the adsorption kinetics were best described by the pseudo-second-order model with R 2 =0.999 for both materials, indicating that a chemical adsorption occurred. The Langmuir, Freundlich, Sips, single-site Langmuir–Freundlich and dual-site Langmuir–Freundlich models were used to analyse the adsorption equilibrium data obtained by the variation of the PD concentration in the aqueous solution and the dual-site Langmuir–Freundlich model presented the best fits, CF: R 2 =0.982 and PPy/CF: R 2 =0.997, indicating that there are two types of sites available for adsorption, homogeneous and heterogeneous, in the assessed materials. In addition, the composite had the best maximum adsorptive capacity, Q =210.07mgg−1, while the CF presented Q =50.33mgg−1. Nano impact Herein, we presented the preparation of cellulose fibre (CF) decorated with polypyrrole (PPy) as an efficient adsorbent for removal of potassium diclofenac (PD) from aqueous medium, which can be used in separation process as solid phase extraction and chromatographic and electrophoretic techniques. The kinetics and isotherms studies showed a great potential of this material for this purpose. The PPy/CF were prepared via in situ polymerization and characterized by FTIR, TG and SEM.
      Graphical abstract image

      PubDate: 2017-02-14T17:32:24Z
      DOI: 10.1016/j.reactfunctpolym.2017.02.002
       
  • Extraction of plutonium using DIPEX immobilized in polystyrene thin films
    • Authors: Hakim Boukhalfa; Dominic S. Peterson; Edward R. Gonzales; Crystal L. Tulley-Cordova; Sowmitri Tarimala; Stuart D. Ware
      Abstract: Publication date: Available online 1 February 2017
      Source:Reactive and Functional Polymers
      Author(s): Hakim Boukhalfa, Dominic S. Peterson, Edward R. Gonzales, Crystal L. Tulley-Cordova, Sowmitri Tarimala, Stuart D. Ware
      We previously reported the development of thin films functionalized with P,P′-di(2-ethylhexyl) methanediphosphonic acid (DIPEX) applied to the extraction and analysis (by alpha spectrometry) of actinide samples. Here we report the full characterization of the films' ability to extract Pu(III), Pu(IV), Pu(V), Pu(VI), and colloidal Pu(IV) under various chemical conditions. For all oxidation states, plutonium partitioning onto DIPEX-polystyrene thin films was less effective than that onto liquid DIPEX. The weight distribution ratios calculated for the thin film extraction efficiency for the different oxidation states were Pu(IV)>Pu(III)>Pu(VI)≅Pu(V)≅colloidal Pu(IV) and were >103 times lower than the distribution ratios observed for liquid DIPEX. Application of the DIPEX-polystyrene thin films for the qualitative processing of contaminated soil samples was very effective; however, the films were less effective for the processing of large water samples with trace levels of plutonium.

      PubDate: 2017-02-03T09:04:27Z
      DOI: 10.1016/j.reactfunctpolym.2017.01.008
       
  • Fabrication and gas sensing behavior of poly(3,4-ethylenedioxythiophene)
           coated polypropylene fiber with engineered interface
    • Authors: Xingping Wang; Si Meng; Wujun Ma; Jürgen Pionteck; Minoj Gnanaseelan; Zhe Zhou; Bin Sun; Zongyi Qin; Meifang Zhu
      Abstract: Publication date: Available online 20 January 2017
      Source:Reactive and Functional Polymers
      Author(s): Xingping Wang, Si Meng, Wujun Ma, Jürgen Pionteck, Minoj Gnanaseelan, Zhe Zhou, Bin Sun, Zongyi Qin, Meifang Zhu
      Conductive composite fibers were successfully fabricated by coating poly(3,4-ethylenedioxythiophene) (PEDOT) layers on the surface of polypropylene-graft-poly(acrylic acid) (PP-g-PAA) fibers through in situ chemical oxidative polymerization. It was found that the adhesion between the conductive PEDOT layers and the modified PP fiber substrates was significantly enhanced due to the electrostatic attractions between PEDOT chains and carboxylic groups of grafted PAA. In this study, we investigated the influence of the 3,4-ethylenedioxythiophene (EDOT) concentration and the oxidant species on the electrical conductivity of the composite fibers, and the result show that the maximum conductivities of PP-g-PAA/PEDOT composite fibers prepared with FeCl3 and iron(III) p-toluenesulfonate (FepTS) as oxidants reached 0.069S/cm and 10.09S/cm, respectively. The composite fibers were applied as a sensor for HCl and NH3 gas detection and exhibited a rapid and reversible response. The influence of the oxidant species on the sensing properties for HCl and NH3 gas detection is further discussed, and some features such as fast response time (less than 2s) and high relative resistance changes (63% for HCl and 110% for NH3 gas) were achieved.

      PubDate: 2017-01-21T10:43:51Z
      DOI: 10.1016/j.reactfunctpolym.2017.01.007
       
  • The influence of adding functionality to dispersant and particle core
           compositions in non-aqueous dispersion polymerization
    • Authors: Weiwei Yang; Robin A. Hutchinson
      Abstract: Publication date: Available online 14 January 2017
      Source:Reactive and Functional Polymers
      Author(s): Weiwei Yang, Robin A. Hutchinson
      Nano-sized polyacrylate colloids (<200nm) at high solids level (~60wt%) are prepared via non-aqueous dispersion (NAD) semibatch polymerization using n-butyl methacrylate (BMA)-based macromer dispersants of varying chain lengths and levels of functionality provided by incorporation of 2-hydroxyethyl methacrylate (HEMA) comonomer. The effect of building the complexity of the core polymer recipe from methyl acrylate homopolymer to a five-monomer composition is systematically studied. While average particle size increased with the introduction of functional comonomers, the resulting NAD systems remained stable for all core compositions using both BMA macromers and a copolymer macromer containing 5mol% HEMA. However, introduction of the HEMA functionality to the dispersant at levels of >5mol% led to destabilization of the dispersion. The polarity differences between the core compositions and dispersant polymers and the mixed continuous medium, as represented by Hansen solubility parameters, are qualitatively used to interpret the nucleation of particles and the effectiveness of the dispersants.
      Graphical abstract image

      PubDate: 2017-01-21T10:43:51Z
      DOI: 10.1016/j.reactfunctpolym.2017.01.005
       
  • Multi-layer dextran-decorated poly(glycidyl methacrylate)-co-divinyl
           benzene copolymer matrices enabling efficient protein chromatographic
           separation
    • Authors: Kun Zhang; Qiang Li; Hong Fan; Suning Li; Yue Su; Lan Zhao; Yongdong Huang; Dan Wang; Zhigang Zhang; Zhiguo Su; Guanghui Ma
      Abstract: Publication date: Available online 12 January 2017
      Source:Reactive and Functional Polymers
      Author(s): Kun Zhang, Qiang Li, Hong Fan, Suning Li, Yue Su, Lan Zhao, Yongdong Huang, Dan Wang, Zhigang Zhang, Zhiguo Su, Guanghui Ma
      A strategy to prepare natural polysaccharide-decorated pGMA-DVB by grafting dextran groups was proposed for the development of efficient protein chromatographic separation. Prepared pGMA-DVB microspheres were covalently decorated with dextran through a three-step scheme. Firstly, residual vinyl groups on polymer particles were converted to epoxy groups. Secondly, one layer of dextran was covalently coupled on the microspheres by reacting with epoxy groups in solvent. Thirdly, multi-layer dextran was grafted to microspheres in alkali aqueous solutions. The dextran-decorated microspheres named pGMA-DVB-Dextran were characterized by Fourier transform infrared spectra, scanning electron microscope, atomic force microscopy, laser scanning confocal microscope, and protein adsorption experiment. Consequently, compared to several commercial hydrophilic beads such as Sepharose® 4FF and POROS® OH, the permeability and hydrophilicity of the modified microspheres were improved, the contact angle decreased from 153° to 0°, and nonspecific adsorption of proteins was decreased to zero. The covalently drafting amount of dextran onto pGMA-DVB was increased to 241.86mg/mL microspheres, and the dextran layers were stable after washing with 1M HCL/NaOH solutions. Functional ligands such as Protein A or DEAE coupled to pGMA-DVB-Dextran can be conveniently used to separation model protein, IgG or BSA, with >99.5% recovery yield and high dynamic binding capacity, respectively.

      PubDate: 2017-01-14T10:36:15Z
      DOI: 10.1016/j.reactfunctpolym.2017.01.003
       
  • Chemically modified natural rubber latex - poly(vinyl alcohol) blend
           membranes for organic dye release
    • Authors: Janisha Jayadevan; Rosamma Alex; Unnikrishnan Gopalakrishnapanicker
      Abstract: Publication date: Available online 5 January 2017
      Source:Reactive and Functional Polymers
      Author(s): Janisha Jayadevan, Rosamma Alex, Unnikrishnan Gopalakrishnapanicker
      Novel blend membranes were prepared from chemically modified natural rubber latex (NRL) and poly(vinyl alcohol) (PVA) for release application. Chemical modification of NRL was done by grafting (dimethylaminoethyl methacrylate) (DMAEMA) onto NR particles by using a redox initiator system viz; cumene hydroperoxide/tetraethylenepentamine (CHP/TEPA), followed by dialysis for purification. The grafting was confirmed by dynamic light scattering (DLS), fourier transform infrared (FT-IR) spectroscopy and nuclear magnetic resonance spectroscopy (NMR). The grafted NRL was subsequently blended with PVA to make uniform membranes by solvent casting at 60±2°C. The blend membranes were characterised by FT-IR spectroscopy, X-ray diffractometry (XRD) and thermogravimetry (TGA). Moisture uptake, swelling and water contact angle experiments showed an increased hydrophilicity when the PVA content in the blend membranes was increased. Scanning electron microscopic investigations indicated the formation of pores in the membranes after a leaching cycle. The potential of the membrane for the use in the release application was tested with model organic dyes rhodamine B, methyl orange and fluorescein. Results from the release study indicate that the membranes can be used for the release of cationic dyes.

      PubDate: 2017-01-06T10:27:11Z
      DOI: 10.1016/j.reactfunctpolym.2017.01.001
       
  • Microgels from microfluidic templating and photoinduced crosslinking of
           cinnamylidene acetic acid modified precursors
    • Authors: D. Ceylan Tuncaboylu; C. Wischke; F. Störmann; A. Lendlein
      Abstract: Publication date: Available online 27 December 2016
      Source:Reactive and Functional Polymers
      Author(s): D. Ceylan Tuncaboylu, C. Wischke, F. Störmann, A. Lendlein
      So far, a number of approaches to synthesize microgel networks have been followed, while only in few cases a detailed control of the network architecture has been possible. Here, the photoinduced [2+2] cycloaddition reaction of cinnamylidene acetic acid (CAA) moieties coupled to four-arm star shaped oligo(ethylene glycol) (OEG) precursors was explored for the creation of microgels with defined polymer network structures. Based on a rational solvent selection and precursor dispersion in glass-capillary microfluidics, microgels could be successfully prepared by the proposed synthesis approach. Model reactions confirmed a quantitative network formation. Therefore, compared to common radical polymerization for microgel crosslinking, CAA-dimerization may be an alternative approach particularly when well defined network structures are desired.

      PubDate: 2017-01-06T10:27:11Z
      DOI: 10.1016/j.reactfunctpolym.2016.12.015
       
  • Imidazole-substituted ROMP polymers: Post-modification of
           poly(norbornenediester) derivatives with aminolysis reactions
    • Authors: Bengi Özgün Öztürk; Elif Yakut; Elif Ak; Solmaz Karabulut Şehitoğlu
      Pages: 22 - 29
      Abstract: Publication date: February 2017
      Source:Reactive and Functional Polymers, Volume 111
      Author(s): Bengi Özgün Öztürk, Elif Yakut, Elif Ak, Solmaz Karabulut Şehitoğlu
      In this study, ring-opening metathesis polymerization (ROMP) polymers bearing imidazole and morpholine functionalities were synthesized using an efficient and inexpensive post-modification procedure. First, dimethyl-5-norbornene-2,3-dicarboxylate was polymerized (Mn: 130kDa, Ð: 1.23) in the presence of Grubbs third-generation catalysts through ROMP reactions. Second, these ROMP polymers were modified using octylamine, 1-(3-aminopropyl)imidazole, and 1-(3-aminopropyl)morpholine in the presence of catalytic amounts of tin(II)hexanoate; Sn(Oct)2, titanium(IV)isopropoxide; Ti(O-i-Pr)4; and 1,5,7-triazabicyclo[4.4.0]dec-5-ene. Modified polymers were characterized by 1H, 13C NMR, FT-IR, differential scanning calorimetry, thermogravimetric analysis, and gel permeation chromatography. Quantitative conversions were achieved using 1-(3-aminopropyl)imidazole as a modification agent in the presence of 10% Sn(Oct)2.
      Graphical abstract image

      PubDate: 2016-12-19T09:00:32Z
      DOI: 10.1016/j.reactfunctpolym.2016.12.008
      Issue No: Vol. 111 (2016)
       
  • Glycyrrhetinic acid-modified PEG-PCL copolymeric micelles for the delivery
           of curcumin
    • Authors: Runliang Feng; Peizong Deng; Zhimei Song; Wei Chu; Wenxia Zhu; Fangfang Teng; Feilong Zhou
      Pages: 30 - 37
      Abstract: Publication date: February 2017
      Source:Reactive and Functional Polymers, Volume 111
      Author(s): Runliang Feng, Peizong Deng, Zhimei Song, Wei Chu, Wenxia Zhu, Fangfang Teng, Feilong Zhou
      In this study, glycyrrhetinic acid (GA) was conjugated with mono amino poly (ethylene glycol)-b-poly (ε-caprolactone) (H2N-PEG-PCL) with succinate linker to obtain the GA-modified PEG-PCL (GA-PEG-PCL). By way of thin film hydration method, curcumin was encapsulated into GA-PEG-PCL copolymer to form stable micelles with 93.76% of encapsulation efficiency and 11.93% of drug loading capacity. The micelles enhanced curcumin's water-solubility to 1.87mg/ml, being 1.70×105 times higher than free curcumin. X-ray diffraction and FT-IR analysis confirmed the encapsulation of CUR into copolymeic micelles with an amorphous state. Hemolysis datum of blank micelles showed its biocompatibility. Compared with GA-unconjugated micelles, curcumin-loaded GA-PEG-PCL micelles showed slower in vitro release of drug, but they displayed better in vitro cytotoxicity against HepG2 at about 40μM because of its selective accumulation in HepG2 cells induced by GA. The results showed that GA-PEG-PCL copolymer could be a promising drug carrier for liver targeted drug delivery.

      PubDate: 2016-12-19T09:00:32Z
      DOI: 10.1016/j.reactfunctpolym.2016.12.011
      Issue No: Vol. 111 (2016)
       
  • Mechanism of modulus improvement for epoxy resin matrices: A molecular
           dynamics simulation
    • Authors: Wenqing Zhang; Yang Qing; Weihong Zhong; Gang Sui; Xiaoping Yang
      Pages: 60 - 67
      Abstract: Publication date: February 2017
      Source:Reactive and Functional Polymers, Volume 111
      Author(s): Wenqing Zhang, Yang Qing, Weihong Zhong, Gang Sui, Xiaoping Yang
      Theoretical modulus of three kinds of epoxy matrices, including diethylene toluene diamine (DETDA)/4,5-epoxyclyclohexyl-1,2-diglycidyldiformate(TDE85), m-phenylenediamine (MPD)/TDE85 and single-walled carbon nanotube (SWCNT) reinforced DETDA/TDE85 were investigated via molecular dynamics (MD) simulation to establish the structure–property relationships. The flexibility and mobility of molecular chains, the packing ability of cross-linked chain segment, the fraction of free volume of epoxy resins and the cohesive energy density in different epoxy systems were analyzed in detail, respectively. The MD simulation results showed that both the slight modification in the diamine structure and the introduction of SWCNTs can result in significant changes in the microstructure parameters of epoxy matrix, however, the modulus improvement mechanisms through changing curing agents and incorporating SWCNT into epoxy matrix had similarities and differences. The MD simulation method will be of great value in predicting and analyzing some performance closely related to the microstructure parameters for the different cross-linked resin system and its composite materials.
      Graphical abstract image

      PubDate: 2016-12-27T10:16:11Z
      DOI: 10.1016/j.reactfunctpolym.2016.12.014
      Issue No: Vol. 111 (2016)
       
  • Versatile synthesis of comb-shaped poly(lactic acid) copolymers with
           poly(acrylic acid)-based backbones and carboxylic acid end groups
    • Authors: Pavel Kucharczyk; Jiri Zednik; Petr Humpolicek; Zdenka Capakova; Vladimir Sedlarik
      Abstract: Publication date: Available online 21 December 2016
      Source:Reactive and Functional Polymers
      Author(s): Pavel Kucharczyk, Jiri Zednik, Petr Humpolicek, Zdenka Capakova, Vladimir Sedlarik
      This paper focuses on preparing and characterizing nonlinear, highly carboxylic-functionalized poly(lactic acid) copolymer prepared through a reaction between poly(acrylic acid) and lactic acid. The resultant copolymer exhibits a comb architecture, in which poly(acrylic) acid creates the backbone and poly(lactic acid) its side arms. Thorough analysis was conducted on the molecular weight of polymers by gel permeation chromatography through triple detection of light-scattering and viscometry. Each copolymer property was studied in detail. Finally, cytotoxicity assay was also performed. Results showed that comb and multi-comb macromolecular architectures co-existed in the sample and that their size and amount are easily tuneable by ratio of the initial reactant.

      PubDate: 2016-12-27T10:16:11Z
      DOI: 10.1016/j.reactfunctpolym.2016.12.012
       
  • Progress on nanocrystalline cellulose biocomposites
    • Authors: Nurhidayatullaili Muhd Julkapli; Samira Bagheri
      Abstract: Publication date: Available online 21 December 2016
      Source:Reactive and Functional Polymers
      Author(s): Nurhidayatullaili Muhd Julkapli, Samira Bagheri
      Nanocrystalline cellulose (NCC) a rigid rod-like nanoscale material, can be produced from cellulosic biomass including wood and non-wood based materials in powder, liquid or gel form by acid and chemical hydrolysis. Owing to its unique and exceptional renewability, biodegradability, mechanical, physicochemical properties and characteristics of abundance, the incorporation of a small amount of NCC to the materials matrix (polymer, ceramic and/or metal) enhances the mechanical strength of the latter by several orders of magnitudes. Besides, NCC as a material derived from natural sources has no serious environmental concerns, providing further impetus for the development and applications of this green and renewable biomaterial to fabricate lightweight and biodegradable composites. Surface functionalization of NCC remains the main focus of NCC research to tailor its properties for dispersion in hydrophilic and hydrophobic media. It is of uttermost importance to develop tools and protocols for imaging of NCC in a complex matrix and quantify its reinforcement, antimicrobial, stability, hydrophilicity and biodegradability effect. This review highlights NCC biocomposites, preparation, modification, and potential applications.

      PubDate: 2016-12-27T10:16:11Z
      DOI: 10.1016/j.reactfunctpolym.2016.12.013
       
  • Miscibility of polyimide blends: Physicochemical characterization of two
           high performance polyimide polymers
    • Authors: Saeed Mazinani; Siavash Darvishmanesh; Rouzbeh Ramezani; Bart Van der Bruggen
      Abstract: Publication date: Available online 16 December 2016
      Source:Reactive and Functional Polymers
      Author(s): Saeed Mazinani, Siavash Darvishmanesh, Rouzbeh Ramezani, Bart Van der Bruggen
      The intermolecular interactions and miscibility behavior of two polyimide blend systems, Extem/Matrimid and Extem/U-Varnish, in compositions of 100/0, 80/20, 50/50, 20/80, 0/100 have been evaluated. The polymer blend systems have been characterized by different analytical techniques such as optical microscopy, Differential Scanning Calorimetry (DSC), Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD) and rheological measurements. DSC results for the Extem/U-Varnish system showed the existence of a single glass transition temperature (Tg) in each composition, suggesting the miscibility of the blends, whereas DSC analysis of Extem/Matrimid system indicated immiscibility but compatibility between two polymers. In order to study the specific interactions between Extem and U-Varnish polymers, the Tgs of the polymer blends were estimated by theoretical equations and compared with experimental data. The empirical Tg values formed a concave curve as a function of composition and exhibited a positive deviation from the linearity, indicating the presence of specific interactions between Extem and U-Varnish polymer chains; this was confirmed by FTIR spectra. Interactions between studied polymer systems and four aprotic solvents including N-methyl-2-pyrrolidone (NMP), Dimethylacetamide (DMAc), Dimethylformamide (DMF) and Dimethyl sulfoxide (DMSO) were assessed on the basis of the difference between their solubility parameters. Among the selected solvents, DMAc showed the highest affinity with both blend systems. XRD patterns and rheological behavior of Extem/U-Varnish system revealed that the crystalline nature and viscosity of the blend polymers decreases as the ratio of Extem/U-Varnish increases. As an overall conclusion, Extem and U-Varnish were found to constitute a miscible pair at a molecular level over the entire composition range whereas Extem and Matrimid could not form a miscible blend.

      PubDate: 2016-12-19T09:00:32Z
      DOI: 10.1016/j.reactfunctpolym.2016.12.010
       
  • Selenide-containing high refractive index polymer material with adjustable
           refractive index and Abbe's number
    • Authors: Huinan Jiang; Xiangqiang Pan; Na Li; Zhengbiao Zhang; Jian Zhu; Xiulin Zhu
      Abstract: Publication date: Available online 8 December 2016
      Source:Reactive and Functional Polymers
      Author(s): Huinan Jiang, Xiangqiang Pan, Na Li, Zhengbiao Zhang, Jian Zhu, Xiulin Zhu
      Poly(glycidyl methacrylate) (PGMA) was synthesized by Fe(0)-mediated living radical polymerization followed with post-modification by PhSeZnCl. A series of selenide functionalized PGMAs with different selenium concentrations and molecular weights were obtained. The introduction of selenide groups into PGMA resulted in a polymer with high refractive index. The relationships between the concentration of selenium, degree of polymerization and refractive index were investigated. Results showed that the refractive index of the final polymer could be adjusted by the concentration of selenium and degree of polymerization, which provided a useful way to fabricate polymeric materials with adjustable refractive index.

      PubDate: 2016-12-11T10:58:23Z
      DOI: 10.1016/j.reactfunctpolym.2016.12.007
       
  • Low molecular chitosan–(poly)nitroxides: Synthesis and evaluation as
           antioxidants on free radical-induced erythrocyte hemolysis
    • Authors: Vasily D. Sen; Ekaterina M. Sokolova; Nikolai I. Neshev; Alexander V. Kulikov; Evgeny M. Pliss
      Abstract: Publication date: Available online 7 December 2016
      Source:Reactive and Functional Polymers
      Author(s): Vasily D. Sen, Ekaterina M. Sokolova, Nikolai I. Neshev, Alexander V. Kulikov, Evgeny M. Pliss
      Water-soluble chitosan-(poly)nitroxides (CPNs), differing in molecular weight of the saccharide backbone and the nature of nitroxide radical, were obtained and characterized. Fractions of modified glucosamines were in the range 0.15–0.28. The dependence of delay time of 2,2-azobis-2-methylpropanimidamide dihydrochloride (AAPH)-induced erythrocyte hemolysis on the concentration of CPNs and data of electron paramagnetic resonance (EPR) spectra indicate their binding to the cell membrane. Because of this binding, CPNs demonstrate identical delay times of hemolysis at concentrations ~100 times lower than structurally similar low molecular nitroxides. Due to easier oxidation of piperidine nitroxide by radicals RO2 to oxoammonium cations, CPNs with attached 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) more effectively inhibit hemolysis than their counterparts with 2,2,5,5-tetramethylpyrroline-1-oxyl. Recycling of nitroxides, presumably, take place through the reaction of oxoammonium cations with common biological reductants. Taken together, our study suggests that CPNs are of interest both as biologically active compounds and as research instruments.

      PubDate: 2016-12-11T10:58:23Z
      DOI: 10.1016/j.reactfunctpolym.2016.12.006
       
  • Preparation and properties of quaternary ammonium chitosan-g-poly(acrylic
           acid-co-acrylamide) superabsorbent hydrogels
    • Authors: Guanghua He; Wanwan Ke; Xiang Chen; Yahui Kong; Hua Zheng; Yihua Yin; Weiquan Cai
      Abstract: Publication date: Available online 6 December 2016
      Source:Reactive and Functional Polymers
      Author(s): Guanghua He, Wanwan Ke, Xiang Chen, Yahui Kong, Hua Zheng, Yihua Yin, Weiquan Cai
      Quaternary ammonium chitosan-g-poly(acrylic acid-co-acrylamide) superabsorbent hydrogels were successfully synthesized from acrylic acid (AA), acrylamide (AM) and quaternary ammonium chitosan with high substitution degree. They were prepared using potassium persulfate (KPS) as an initiator and N,N′-methylenebisacrylamide (MBA) as a crosslinker respectively. The structure and morphology of the superabsorbent hydrogel were characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The water absorbency and antibacterial activities of the superabsorbent hydrogels against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were investigated. The introduction of quaternary ammonium chitosan made the antibacterial activity improved. The crosslinker, initiator and AM contents had certain influences on the water absorbency as well as the antibacterial activity against E. coli. The AM could enhance the hydrogel strength apparently. In addition, the AM (the content was 10wt%) could increase the water absorbency in 0.9wt% NaCl solution obviously. The superabsorbent hydrogel also had pH sensitive property.

      PubDate: 2016-12-11T10:58:23Z
      DOI: 10.1016/j.reactfunctpolym.2016.12.001
       
  • Novel iodo-containing poly(arylene ether ketone)s as intermediates for
           grafting perfluoroalkyl sulfonic acid groups
    • Authors: Siyuan Liu; Wu Luo; Hanyu Zhang; Xiaobai Li; Wei Hu; Michael D. Guiver; Baijun Liu
      Abstract: Publication date: Available online 6 December 2016
      Source:Reactive and Functional Polymers
      Author(s): Siyuan Liu, Wu Luo, Hanyu Zhang, Xiaobai Li, Wei Hu, Michael D. Guiver, Baijun Liu
      A synthetic approach to poly(arylene ether ketones) grafted with super-acidic perfluoroalkyl-sulfonic-acids is reported. A series of iodo-containing poly(arylene ether ketone)s derived from a 4-iodophenylated hydroquinone monomer were synthesized by aromatic nucleophilic substitution (SNAr). The iodo-containing polymers were functionalized via the Ullmann reaction to give poly(arylene ether ketone)s grafted with perfluoroalkyl-sulfonic-acid. The perfluoroalkyl-sulfonic-acid functionalized aromatic polymers were investigated as proton exchange membranes (PEM). The membranes had good overall properties of thermal-oxidative stability, mechanical strength, methanol permeability and proton conductivity. A membrane with IEC ~1.37meqg−1 had a proton conductivity of 0.088Scm−1 at 100°C, which was higher than many sulfonated hydrocarbon PEMs with similar IEC values.

      PubDate: 2016-12-11T10:58:23Z
      DOI: 10.1016/j.reactfunctpolym.2016.12.002
       
  • A methacryl ethyl-functionalized soluble polypyrrole: Synthesis,
           characterization, and potentiality in rapid fabrication of
           high-aspect-ratio pillar arrays
    • Authors: Guowei Lv; Shihu Zhang; Guolong Wang; Jinyou Shao; Hongmiao Tian; Demei Yu
      Abstract: Publication date: Available online 6 December 2016
      Source:Reactive and Functional Polymers
      Author(s): Guowei Lv, Shihu Zhang, Guolong Wang, Jinyou Shao, Hongmiao Tian, Demei Yu
      A methacryl ethyl-functionalized soluble polypyrrole was designed and prepared by chemical oxidative polymerization for rapid fabrication of high-aspect-ratio pillar arrays. The chemical structures of the pyrrole derivative and the corresponding polypyrrole were characterized by FTIR and 1H NMR. The polypyrrole with a weight-average molecular weight (Mw) of 7376 exhibits good solubility in several organic solvents, favorable thin film-forming ability and two UV–Vis absorption peaks at 280 and 380nm in tetrahydrofuran solution. The dilute chloroform solution of the polypyrrole is a Newtonian fluid with a low viscosity and shows a significant increase in the electrical conductivity with increasing the polypyrrole content. Moreover, an insulating photoresist can be transformed into a conductive photoresist by doping this polypyrrole. Electrowetting driven structure formation experiments have confirmed that the conductive photoresist can fulfill rapid fabrication of higher-aspect-ratio pillar arrays compared with the insulating photoresist.
      Graphical abstract image

      PubDate: 2016-12-11T10:58:23Z
      DOI: 10.1016/j.reactfunctpolym.2016.12.005
       
  • Maleic anhydride functionalization of OSTE based coatings via thiol-ene
           “Click” reaction for the covalent immobilization of xylanase
    • Authors: Emrah Çakmakçi; Başak Yuce-Dursun; Serap Demir
      Abstract: Publication date: Available online 3 December 2016
      Source:Reactive and Functional Polymers
      Author(s): Emrah Çakmakçi, Başak Yuce-Dursun, Serap Demir
      Combination of Off-Stoichiometry Thiol-Ene (OSTE) polymers with thiol-ene “Click” reaction is a versatile method for the development of advanced functional materials. In this study OSTE based photocurable coating materials with excess thiol groups on the surface were prepared and functionalized with maleic anhydride via thiol-ene “Click” reaction. Xylanase enzyme was then covalently immobilized onto these coatings. Maleic anhydride functionalization of the prepared OSTE coatings was proved by FTIR and contact angle measurements. The developed functional support was found to have high affinity for xylanase enzyme and the immobilization capacity was determined as 212mgg−1. Almost 100% of immobilization yield was achieved. Immobilization significantly improved the stability of the xylanase at pH values over 6.5 and temperatures exceeding 60°C. Moreover the immobilized xylanase exhibited superior reusability and storage stability compared to free xylanase.

      PubDate: 2016-12-05T12:32:29Z
      DOI: 10.1016/j.reactfunctpolym.2016.11.006
       
  • Novel phenolic antioxidant-functionalized dendritic polyethylene:
           Synthesis by tailor-made nickel(II) α-diimine-catalyzed copolymerization
           and its characteristics as non-releasing additive
    • Authors: Zahra Balzadeh; Hassan Arabi
      Abstract: Publication date: Available online 25 November 2016
      Source:Reactive and Functional Polymers
      Author(s): Zahra Balzadeh, Hassan Arabi
      This work describes a simple one-pot and controlled synthetic method to generate migration-resistant bio-friendly tailor-made antioxidants through dendritic polyethylene (DPE)–sterically hindered phenolic antioxidant (SHPA) copolymerization by coordination polymerization using MAO-activated nickel(II)-α-diimine catalyst. The antioxidant tethering into the polymer chain by chain walking catalysts leads to adjustable copolymer architectures possessing different thermal features. It was found that oxidation induction time could be fine-tuned (from 2 to 36min) by appropriate SHPA content selection and PE altering (from 10 to 0.5bar of gage). Furthermore, the chemical composition analysis of DPE–SHPA copolymer shows 0.6wt% SHPA incorporation (approximately 80% conversion) besides a dendritic architecture, containing 123 branches per 1000 carbon atoms and AFM images resembling semi-spherical topology. The migration resistance of the synthesized copolymers and their application as non-releasing additives are also investigated.

      PubDate: 2016-11-27T14:45:28Z
      DOI: 10.1016/j.reactfunctpolym.2016.11.005
       
  • Amphiphilic block-random copolymer surfactants with tunable
           hydrophilic/hydrophobic balance for preparation of non-aqueous dispersions
           by an emulsion solvent evaporation method
    • Authors: Naofumi Ezaki; Yoshifumi Watanabe Hideharu Mori
      Abstract: Publication date: Available online 16 November 2016
      Source:Reactive and Functional Polymers
      Author(s): Naofumi Ezaki, Yoshifumi Watanabe, Hideharu Mori
      The structural effects of amphiphilic block-random copolymers composed of stearyl methacrylate (SMA) and diethanolamine-modified glycidyl methacrylate (DEAGMA), poly(SMA)-b-poly(DEAGMA-r-SMA)s on their surfactant efficacy for a non-aqueous emulsion solvent evaporation method were investigated. Three series of block-random copolymers (i) with different amounts of DEAGMA in the poly(DEAGMA-r-SMA) segment and (ii, iii) with different chain lengths of each segment were synthesized by reversible addition-fragmentation chain transfer polymerization. The surfactant efficacies of these copolymers were investigated in terms of the interfacial tension and modulus, size, and stability of the emulsion and dispersion. Suitable comonomer composition and chain lengths of both segments produced stable emulsions and dispersions with small particle sizes (<200nm).

      PubDate: 2016-11-21T03:11:01Z
       
  • Effect of reactive functionalization on properties and degradability of
           poly(lactic acid)/poly(vinyl acetate) nanocomposites with cellulose
           nanocrystals
    • Authors: Minhaz-Ul Haque; Debora Puglia Elena Fortunati Mariano Pracella
      Abstract: Publication date: Available online 15 November 2016
      Source:Reactive and Functional Polymers
      Author(s): M. Minhaz-Ul Haque, Debora Puglia, Elena Fortunati, Mariano Pracella
      Nanocomposites of poly(lactic acid) (PLA) containing cellulose nanocrystals (CNCs) were prepared by dispersion of CNCs in aqueous poly(vinyl acetate) (PVAc) emulsion followed by melt extrusion with PLA. Functionalization of PVAc by radical grafting of glycidyl methacrylate (PVAc-GMA) was carried out during PVAc polymerization by using ammonium cerium (IV) nitrate as the initiator. The morphology, phase interactions, thermal and mechanical properties and degradability in composting of blends (PLA/PVAc, PLA/PVAc-GMA) and nanocomposites (PLA/PVAc/CNC, PLA/PVAc-GMA/CNC) containing 3wt% CNC were examined by FESEM, AFM, FT-IR, DSC and tensile tests. The study of degradability demonstrated that the disintegration rate of PLA/PVAc-GMA/CNC in soil was higher than that of PLA/PVAc/CNC, likely because the epoxy groups of GMA accelerated the biodegradation rate through the formation of radicals.
      Graphical abstract image

      PubDate: 2016-11-21T03:11:01Z
       
 
 
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